Casimir pistons with hybrid boundary conditions

TL;DR

This paper investigates the Casimir effect in piston configurations with hybrid boundary conditions, revealing that such setups always produce a repulsive force, contrasting with Dirichlet-only conditions.

Contribution

It introduces the analysis of Casimir pistons with hybrid boundary conditions, demonstrating the universal repulsive nature of the force in these cases.

Findings

Casimir force is always repulsive with hybrid boundary conditions.

Contrasts with Dirichlet boundary conditions where force can be attractive or repulsive.

Analysis covers one to three-dimensional piston configurations.

Abstract

The Casimir effect giving rise to an attractive or repulsive force between the configuration boundaries that confine the massless scalar field is reexamined for one to three-dimensional pistons in this paper. Especially, we consider Casimir pistons with hybrid boundary conditions, where the boundary condition on the piston is Neumann and those on other surfaces are Dirichlet. We show that the Casimir force on the piston is always repulsive, in contrast with the same problem where the boundary conditions are Dirichlet on all surfaces.